Input/output connector with heat sink

ABSTRACT

A card has a rear portion with contact pads provided therein and has an input/output (I/O) connector assembly mounted on a first side with the I/O connector assembly including a receptacle connector positioned in a cage. A heat sink assembly is mounted on the cage and is configured to extend into the cage so as to help cool an inserted plug module. If desired a second heat sink can be mounted on a second side of the card. The second heat sink can extend through an aperture in the card into a port defined by the I/O connector assembly so that a module inserted into the port can be cooled from two sides. The card can be configured to be mounted

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Appln. Ser. No.62/820,608, filed Mar. 19, 2019, and to U.S. Provisional Appln. Ser. No.62/826,009, filed Mar. 29, 2019.

TECHNICAL FIELD

This disclosure relates to the field of input/output (I/O) connectors,more specifically to I/O connectors suitable for use in high data rateapplications.

DESCRIPTION OF RELATED ART

Input/output (I/O) connectors are commonly used to provide transmissionof signals between two devices. Increasingly I/O connectors are beingused to support data rates and distances that make the use of passivecables assemblies unfeasible from a theoretical standpoint. As a result,many such cable assemblies are being provided as optical cables.

Optical cables, while more expensive, allow a system to be set up thatcan provide high data rates over long distances. For example, 100 Gb canbe supported over a quad small form factor pluggable (QSFP) connectorsystem at distances of 100 meters (or more), a distance that would beimpossible for a passive cable to support. One issue with using opticalcables, however, is that the thermal energy emitted by the transceivermakes it difficult to pack a number of ports in a single box or chassis.As a result, certain individuals would appreciate a design that couldhelp improve how the thermal energy was managed.

Connectors have been known to provide a riding heat sink to help providecooling, such as is disclosed in U.S. Pat. No. 6,749,448. Attempts toimprove on this design have had some success but often the improvementsare either too expensive or provide less effective cooling, such as thedesign disclosed by CN UM 206789813. Thus, certain individuals wouldappreciate additional improvements in cooling technology.

SUMMARY

A card assembly, which includes a card that can be a conventionalcircuit board with contact pads provided on one edge, is provided thathas a input/output (I/O) connector assembly mounted on it and the cardassembly can be configured to have a heat sink assembly on two opposingsides of the card. In an embodiment, one of the heat sinks extendsthrough the card. The card can be configured to be mounted vertically orhorizontally.

In one embodiment a card with I/O connector assemblies that define portsis mounted in a vertical orientation. A heat sink assembly can beprovided on both sides of the card. The heat sink assembly on both sidescan be configured to be a riding heat sink and both heat sink assembliescan extend into the respective port such that an inserted plug modulecan be cooled from both sides. In an embodiment, one of the heat sinkassemblies extends through one or more apertures in the card.

In another embodiment a card with an I/O connector assembly that definestwo stacked ports is mounted on the card and the card is arranged in ahorizontal direction A heat sink assembly can be provided on both sidesof the card. Both of the heat sink assemblies can be a riding heat sinkand can extend into the respective ports such that an inserted plugmodule can be cooled regardless of whether it is inserted in the top orbottom port sides. In an embodiment, one of the heat sink assembliesextends through the card. An internal heat sink

In another embodiment, a card with an I/O connector assembly thatdefines a port is mounted thereon is configured in a horizontaldirection. A heat sink assembly can be provided on both sides of thecard. The heat sink assemblies can be configured as a riding heat sinkand can extend into the port from two opposing sides such that aninserted plug module can be cooled from both sides. In an embodiment,one of the heat sinks extends through the card.

BRIEF DESCRIPTION OF THE DRAWINGS

The present application is illustrated by way of example and not limitedin the accompanying figures in which like reference numerals indicatesimilar elements and in which:

FIG. 1 illustrates a perspective view of an embodiment of a box with thesides of the box removed.

FIG. 2 illustrates a perspective view of an embodiment of a I/O cageassembly.

FIG. 2A illustrates a perspective view of an embodiment of a heat sink.

FIG. 3 illustrates a perspective view an embodiment of a front face of abox.

FIG. 4 illustrates a perspective view of internal features of a box.

FIG. 5 illustrates a perspective view of features of a front face thatcan be used in a box.

FIG. 6 illustrates a perspective view of a plurality of card assemblies.

FIG. 7 illustrates a perspective view of a card assembly.

FIG. 8 illustrates another perspective view of the card assemblydepicted in FIG. 7.

FIG. 9 illustrates a perspective view of another embodiment of a cardassembly.

FIG. 10 illustrates a simplified perspective view of the embodimentdepicted in FIG. 9.

FIG. 11 illustrates a perspective view of an embodiment of cardassemblies connected to a circuit board.

FIG. 12 illustrates a perspective view of card assemblies arranged in abox system that includes a cable tray.

FIG. 13 illustrates a perspective view of a plurality of card assembliesmounted to a circuit board.

FIG. 14 illustrates another perspective view of the embodiment depictedin FIG. 13.

FIG. 15 illustrates another perspective view of the embodiment depictedin FIG. 13.

FIG. 16 illustrates a simplified perspective view of the embodimentdepicted in FIG. 13.

FIG. 17 illustrates an elevated side view of a port of the I/O connectorassembly.

FIG. 18 illustrates a partially exploded perspective view of the cardassembly in the embodiment depicted in FIG. 16.

FIG. 19 illustrates an exploded perspective view of the card assemblydepicted in FIG. 16 with the card removed.

FIG. 20 illustrates a simplified perspective view of the embodimentdepicted in FIG. 18.

FIG. 21 illustrates a simplified perspective view of the embodimentdepicted in FIG. 16 with the cage and heat sinks removed.

FIG. 22 illustrates another perspective view of the embodiment depictedin FIG. 21.

FIG. 23 illustrates a simplified perspective view of the embodimentdepicted in FIG. 22.

FIG. 24 illustrates another perspective view of the embodiment depictedin FIG. 23.

FIG. 25 illustrates an elevated side view of the embodiment depicted inFIG. 23.

FIG. 26A illustrates a perspective view of another embodiment of aplurality of card assembly supported by a support member.

FIG. 26B illustrates a simplified perspective view of the embodimentdepicted in FIG. 26A.

FIG. 26C illustrates a perspective view of a cross section taken alongline 26C-26C in FIG. 26B.

FIG. 26D illustrates an elevated rear view of the embodiment depicted inFIG. 26B.

FIG. 26E illustrates a simplified partially exploded perspective view ofthe embodiment depicted in FIG. 26B.

FIG. 26F illustrates a partially exploded perspective view of theembodiment depicted in FIG. 26B.

FIG. 26G illustrates a perspective vie of an embodiment of a supportmember suitable for use in the embodiment depicted in FIG. 26B.

FIG. 26H illustrates another perspective view of the embodiment depictedin FIG. 26G.

FIG. 27A illustrates a schematic representation of a box with ahorizontal aligned card assembly.

FIG. 27B illustrates a schematic representation of a card suitable foruse in the embodiment depicted in FIG. 27A.

FIG. 28 illustrates a perspective view of an embodiment of a cardassembly

FIG. 29 illustrates another perspective view of the embodiment depictedin FIG. 28.

FIG. 30 illustrates a perspective view of another embodiment of a cardassembly showing a single cage mounted on the card.

FIG. 31 illustrates a perspective view of a cross section of FIG. 30,taken along line 31-31.

FIG. 32 illustrates a perspective view of a cross section of FIG. 30,taken along line 32-32.

FIG. 33 illustrates a perspective exploded view of the embodimentdepicted in FIG. 30.

FIG. 34 illustrates a perspective view of an embodiment of a cardassembly.

FIG. 35 illustrates a perspective exploded view of the embodimentdepicted in FIG. 34.

FIG. 36 illustrates a perspective view of a cross section of FIG. 34,taken along line 36-36.

FIG. 37 illustrates a perspective view of a cross section of FIG. 34,taken along line 37-37.

DETAILED DESCRIPTION

The detailed description that follows describes exemplary embodimentsand the features disclosed are not intended to be limited to theexpressly disclosed combination(s). Therefore, unless otherwise noted,features disclosed herein may be combined together to form additionalcombinations that were not otherwise shown for purposes of brevity.

FIGS. 1-2A depict an embodiment of a plurality of input/output (I/O)connector assemblies 20 housed in a box 22 which provides for usefulthermal dissipation. The I/O connector assemblies 20 are mounted on andelectrically coupled to a front circuit board 24 which is horizontallymounted in the box 22. The front circuit board 24 is positioned betweenstacked pairs of the I/O connector assemblies 20. The connectorassemblies 20 are coupled to a first rear circuit board ²⁶ that supportsa chip package in a bypass arrangement for transmitting high speedsignals from the I/O connector assemblies 20 to the rear circuit board26. The connector assemblies 20 are also coupled to a second rearcircuit board (not shown) for transmitting low speed signals from theI/O connector assemblies 20 thereto. Plug modules (not shown) aremounted in the I/O connector assemblies 20. The plug modules may be QuadSmall Form Factor (QSFP) transceiver modules or any other desiredtransceiver module (such as, without limitation, SFP, CXP, etc.). Highspeed signals from the plug modules are routed via the I/O connectorassemblies 20 to the rear circuit board 26. Low speed signals and powermay be routed through the front circuit board 24, or may be routed usinga cable, to the second rear circuit board. The embodiment shown in FIGS.1 and 2 works well for situations where there is a certain level ofthermal load, but such a design tends to be marginal when attempting tocool plug modules that output 8-10 (or more) watts. In addition, thefront circuit board 24 may be difficult to package in certaincircumstances.

The box 22 has a front wall 28 having a plurality of pairs of stackedopenings 30 provided therethrough formed in rows and columns. Eachopening 30 extends horizontally relative to side edges 28 a, 28 b of thefront wall 28. As such, a top row 32 of spaced apart openings 30 isprovided, and a bottom row 34 of spaced apart openings 30 is provided,which are spaced apart from each other by a section 36 of the front wall28. As shown, the openings 30 form two sets of 2×6 matrices, however,this is an example embodiment, and the numbers of openings 30 may varyfrom this configuration. The front wall 28 has a plurality of air flowopenings 38 provided therethrough which allow air to flow through thefront wall 28 to cool the I/O connector assemblies 20 mounted therein.Thus, the front wall 28 can be configured to decrease air resistance soas to allow for more air to flow through the box 22 for a given airpressure gradient.

The box 22 is shown with most of the walls removed for purposes ofillustration but typically would include a bottom wall 88, as well asside, rear and top walls (not shown). A frame can be positioned in thebox and can like side walls 42, 44 that extend rearwardly from the frontwall 28 where the frame can help support circuit boards that arepositioned in the box 22.

The front circuit board 24 is mounted in a horizontal orientation and ispositioned to extend rearwardly from the section 36 of the front wall28. As such, the front circuit board 24 is positioned between the toprow 32 of openings 30 and the bottom row 34 of openings 30. Pairs of theI/O connector assemblies 20 are mounted belly to belly on the frontcircuit board 24. As such, a plurality of spaced apart I/O connectorassemblies 20 are mounted on a top surface of the front circuit board 24and a plurality of spaced apart I/O connector assemblies 20 are mountedon a bottom surface of the front circuit board 24.

An example of one of the I/O connector assemblies 20 is shown in FIG. 2.The I/O connector assembly 20 includes a conductive cage 46 having afront end 46 a and a rear end 46 b and which has a port 48 extendingfrom the front end 46 a toward the rear end 46 b thereof, a receptacleconnector (not shown) mounted in the port 48 of the cage 46, a heat sinkassembly 50 mounted to the cage 46, and a cable assembly 52 connected tothe receptacle connector.

The cage 46 includes parallel first and second walls 54, 56 and parallelside walls 58, 60 extending between the first and second walls 54, 56 atopposite side edges thereof. Inner surfaces of the walls 54, 56, 58, 60form the port 48. The second wall 56 does not extend the full length ofthe cage 46 such that an opening (not shown) is formed proximate to therear end 46 b of the cage 46. The wall 54 of the cage 46 includes anopening (not shown) therethrough which is rearward of the front end 46 aof the cage 46. The receptacle connector is inserted into the port 48through the opening formed by the second wall 56 and terminals (notshown) of the receptacle connector extend from the second wall 56.Spring fingers 62 may be provided on the walls 54, 56, 58, 60 to assistin connecting the cage 46 to the respective opening 30 in the front wall28. The cage 46 may be formed by stamping and forming. The cage 46 isthermally conductive and forms a shield assembly for the componentsmounted therein. When the cages 46 are connected to the front wall 28,the front ends 46 a of the cages 46 form ports through the front wall28.

In the embodiment shown in FIGS. 1-2A, the heat sink assembly 50 isformed from a thermally conductive material and includes a heat sink 66and a clip 68 which attaches the heat sink 66 to the wall 54 to the cage46. As shown, the heat sink 66 includes a base 70 having a first surface70 a and a planar second, opposite surface 70 b which extends from afront end 70 c of the base 70 to a rear end 70 d of the base 70, aplurality of conductive fins 72 extending outwardly from the firstsurface 70 a, and a projection 74 extending outwardly from the secondsurface 70 b. The projection 74, as shown, may include a chamfer orangled front portion to ensure smoother engaging with an inserted plugmodule in operation. In an embodiment as shown in the drawings, the fins72 are elongated and extend from the front end 70 c to the rear 70 d,such that elongated channels 76 are formed therebetween. As shown,multiple sets of fins 72 may be provided, with the sets of fins 72 beingseparated by sections 78 of the first surface 70 a of the base 70. In analternative embodiment (not shown), the fins 72 can be formed in anarray of pillars or some other desirable fin pattern/construction asdesired.

The second surface 70 b seats against an outer surface of the wall 54.The projection 74 extends through the opening in the wall 54 of the cage46 and into the port 48 thereof. The clip 68 attaches to the side walls158, 160 to attach the heat sink 66 to the wall 54 of the cage 46, andin an embodiment, the clip 68 is seated in the sections 78.

A plug module (not shown) is inserted through the front end 46 a of thecage 46, into the port 48 and engages with the receptacle connector in aknown manner. The plug module forms a primary electromagneticcontainment and the cage 46 forms a conductive sleeve around the plugmodule. When the plug module is inserted into the cage 46, the plugmodule engages with the projection 74 and with a card slot of thereceptacle connector 90. The clip 68 may allow the base 70 of the heatsink 66 to move away from the wall 54 when the plug module is insertedand engages with the projection 74. To cool the inserted plug module,the projection 74 conducts thermal energy away from the highertemperature plug module toward the fins 72 (that in an embodiment candissipate heat by convection) to help cool the plug module.

The cable assembly 52 includes a plurality of cables 80 connected to thereceptacle connector for transmitting high speed signals from the plugmodule to the first rear circuit board 26, and plurality of cables 82connected to the receptacle connector for transmitting low speed signalsfrom the plug module to the second rear circuit board. The cables 80 areterminated with connectors 84 and the cables 82 are terminated with aconnector 86.

In the embodiment of FIGS. 1-2A, the I/O connector assemblies 20 in thetop row 32 have the wall 56 mounted to the top surface of the frontcircuit board 24 such that the wall 54 forms a top wall and the fins 72extend upwardly from the front circuit board 24. The cages 46 in the toprow 32 may be mounted to the front circuit board 24 either via asurface-mount technology (SMT) operation or via an interference fitusing press-fit tails as is known in the art. The receptacle connectorswithin the cages 46 of the top row 32 of the I/O connector assemblies 20electrically connect with the front circuit board 24 to provide a pathfor the low speed signals and power to pass therethrough. The channels76 between the fins 72 of the connector assemblies 20 in the top row 32align with the air flow openings 38 such that air flows through openings38 and through the channels 76. The I/O connector assemblies 20 in thebottom row 34 have the wall 56 mounted to the bottom surface of thefront circuit board 24 such that the wall 54 forms a bottom wall and thefins 72 extend downwardly from the front circuit board 24. The cages 46in the bottom row 34 may be mounted to the front circuit board 24 eithervia a surface-mount technology (SMT) operation or via an interferencefit using press-fit tails as is known in the art. The receptacleconnectors within the cages 46 of the bottom row 34 of the I/O connectorassemblies 20 electrically connect with the front circuit board 24 toprovide a path for the low speed signals and power to pass therethrough.The channels 76 between the fins 72 of the connector assemblies 20 inthe bottom row 34 align with the air flow openings 38 such that airflows through openings 38 and through the channels 76.

The embodiment shown in FIGS. 1-2A will typically require that the plugmodules in the top row 32 of ports formed by the I/O connectorassemblies 20 have the opposite orientation of the plug modules in thebottom row 34 of ports formed by the I/O connector assemblies 20 so thatboth I/O connector assemblies can use a standard riding heat sinkconfiguration.

A floor 88 of the box 22 can be used to support the cables 80 as thecables 80 extend from the cages 46 to the rear circuit board 26.Alternatively, a tray can be used. If a tray is used, the tray (whichcan be rigidly or flexibly connected to the front connector portion)helps route the cables carrying the high speed signals to placesadjacent the ASIC/computer chip and can help ensure the cables remain ina desired orientation (which may be desirable if a substantial number ofcables are provided).

FIGS. 27A, 27B depict a schematic representation of an embodiment of aplurality of card assemblies 115 that include an input/output (I/O)connector assemblies 120 housed in a box 110 (which may be formed likebox 22 without the top row 32 of openings 30) which provides enhancedthermal dissipation. Specifically, FIGS. 27a -27B illustrate a schematicrepresentation of a horizontal card construction. In an embodiment wherea card assembly 115 is used, a card 124 supports an I/O connectorassembly 120 that includes a heat sink 166. A right-angle connector 220can be provided on a main circuit board 126 and the card 124 can includecontact pads 124 c on the back edge of the card that is configured to beinserted into the right-angle connector 220. As can be appreciated, thecard 124 could also be connected to a main circuit board 126 with cables128.

As depicted, the I/O connector assemblies 120 is positioned in the box110 and positioned in the box is the main circuit board 126 thatsupports a chip package 126 a (which can be any desirable highperformance chip). The connector assemblies 120 are coupled to the rearcircuit board 126 in a bypass arrangement using cables 128 that areconnected to connector system 129 for transmitting high speed signalsfrom the I/O connector assemblies 120 to the chip package 126 a in a lowloss manner. As discussed above, plug modules (not shown) are mated tothe I/O connector assemblies 120. The plug modules may be Quad SmallForm Factor (QSFP) transceiver modules or any other desirable formatsuch as QSFP-DD, SFP, CXP, OSFP, etc. It should be noted that otherembodiments (such as those depicted in FIGS. 3-25) are also intended tohave the cables extending from the respective I/O connector assemblyconnect to a connector system that is adjacent a chip package configuredto receive and/or transmit high speed signals

Turning to FIGS. 28-37, embodiments of horizontally aligned ports areprovided, one in a stacked configuration and one in a single rowversion. In each case the I/O connector assemblies are mounted on acard. In one embodiment the card could include a row of contacts likewhat is shown in FIG. 16 or schematically in FIG. 27B and, like in FIG.27B, the card assembly would be configured to be inserted into a rightangle connector (not shown) so that the ports were provided in ahorizontal manner. Cables, similar to what was depicted in theembodiment depicted in FIGS. 13-25, would extended rearward from the I/Oconnector assembly and provide the high speed signal path. In anotherembodiment, the card could be part of a larger circuit board and cablesfor high speed signals would extend rearward from the I/O connectorassembly similar to what was depicted in the embodiment depicted FIGS.13-25. Alternatively, the I/O connector assembly could omit the bipassconfiguration and just use the card as a standard signal transmissionmedium. The latter construction would be lower performing from a signalintegrity standpoint but could still provide enhanced coolingperformance.

Turning to FIGS. 34-37, a card assembly 115 includes an I/O connectorassembly 120 mounted to a card 124. The I/O connector assembly 120—has aconductive cage 146 has a front end 146 a and a rear end 146 b and thecage 146 defines a port 148 extending from the front end 146 a towardthe rear end 146 b thereof. A receptacle connector 190 is mounted to thecard 124 and is positioned in the port 148 and a first heat sinkassembly 150 is mounted to an upper side of the cage 146 while a secondheat sink assembly 192 is mounted to a lower side of the cage 146, and acable assembly (not shown) can connected to the receptacle connector 190in a manner similar to the embodiment depicted in FIGS. 13-25.

The cage 146 includes parallel top and bottom walls 154, 156 andparallel side walls 158, 160 extending between the top and bottom walls154, 156 at opposite side edges thereof. Inner surfaces of the walls154, 156, 158, 160 form the port 148. The bottom wall 156 does notextend the full length of the cage 146 such that an opening 194 isformed proximate to the rear end 46 b of the cage 46. The bottom wall156 has an opening 196 therethrough which is rearward of the front end46 a of the cage 46. The top wall 154 has an opening 198 therethroughwhich is rearward of the front end 46 a of the cage 46. The openings196, 198 may be aligned with each other. Spring fingers 162 may beprovided on the walls 154, 156, 158, 160 to assist in connecting thecage 146 to the respective opening 30 in the front wall 28. The cage 146may be formed by stamping and forming. The cage 146 is thermallyconductive and forms a shield assembly for the components mountedtherein. When the cage 146 is connected to the front wall 28 of the box22, the front end 146 a of the cage 146 helps define a port that extendsthrough the front wall 28.

The first heat sink assembly 150 is formed from a thermally conductivematerial and includes a heat sink 166 and a clip 168 which attaches theheat sink 166 to the top wall 154 of the cage 146. As shown, the heatsink 166 includes a base 170 having an upper surface 170 a and a planarlower surface 170 b which extends from a front end 170 c of the base 170to a rear end 170 d of the base 170, a plurality of conductive fins 172extending outwardly from the upper surface 170 a, and a projection 174extending outwardly from the lower surface 170 b. The projection 174 hasa planar surface 174 a which spaced from the lower surface 170 b, but isparallel thereto. The distance between the surfaces 174 a, 170 b definesa depth of the projection 174. In an embodiment as shown in thedrawings, the fins 172 are elongated and extend from the front end 170 cto the rear 170 d, such that elongated channels 176 are formedtherebetween. As shown, multiple sets of fins 172 may be provided, withthe sets of fins 172 being separated by sections 178 of the uppersurface 170 a of the base 170. In an alternative embodiment (not shown),the fins 172 are formed in an array of pillars or some other desirablefin construction.

The lower surface 170 b of the base 170 seats against an outer surfaceof the top wall 154. The projection 174 extends through the opening 198in the top wall 154 of the cage 146 and into the port 148 thereof. Theclip 168 is attached to the side walls 158, 160 to attach the heat sink166 to the top wall 154 of the cage 146, and in an embodiment, the clip168 is seated in the sections 178.

The second heat sink assembly 192 is formed from a thermally conductivematerial and includes a heat sink 202 and a clip 204 which attaches theheat sink 202 to the cage 146. As shown, the heat sink 202 includes abase 206 having a lower surface 206 a and a planar upper surface 206 bwhich extends from a front end 206 c of the base 206 to a rear end 206 dof the base 206, a plurality of conductive fins 208 extending outwardlyfrom the lower surface 206 a, and a projection 210 extending outwardlyfrom the upper surface 206 b. The projection 210 has a planar surface210 a which spaced from the upper surface 206 b, but is parallelthereto. The distance between the surfaces 210 a, 206 b defines a depthof the projection 210. In an embodiment as shown in the drawings, thefins 208 are elongated and extend from the front end 206 c to the rear206 d, such that elongated channels 212 are formed therebetween. Asshown, multiple sets of fins 208 may be provided, with the sets of fins208 being separated by sections 278 of the lower surface 206 a of thebase 206. In an alternative embodiment (not shown), the fins 208 areformed in an array of pillars or some other desirable fin arrangement.

The card 124 has an opening 216 provided therethrough. When the cage 144is mounted onto an upper surface 124 a of the card 124, the opening 216aligns with respective opening 196 in the cage 144. As cab beappreciated, while the card assembly in FIGS. 34-37 shows a single I/Oconnector assembly, in alternative embodiments additional I/O connectorassemblies can be provided on the card 124 (provided that the cad 124 ismade larger).

The second heat sink assembly 192 is assembled to the card 124 and tothe cage 146. The upper surface 206 b of the base 206 abuts against alower surface 124 b of the card 124, the projection 210 extends throughthe opening 216 in the card 124 and further extends through the opening196 in the bottom wall 156 and into the port 148. The clip 204 extendsthrough aperture 218 in the card 124 and engage with the side walls 158,160 of the cage 146.

A plug module (not shown) is inserted through the front end 146 a of thecage 146, into the port 148 and engages with the receptacle connector190 in a known manner The plug module forms a primary electromagneticcontainment and the cage 146 forms a conductive sleeve around the plugmodule. When the plug module is inserted into the cage 146, the plugmodule engages with the surfaces 74 a, 210 a of the projections 174, 210and with a card slot of the receptacle connector 190. The clips 168, 204may allow the base 170, 206 of the respective heat sink 166, 202 to moveaway from the respective top and bottom walls 154, 156 when the plugmodule is inserted. To cool the inserted plug module, the fins 172, 208conduct heat away from the plug module mounted in the cage 146 anddissipate heat by convection and radiation. As can be appreciated, sincethe projection 210 extends through both of the card 124 and the bottomwall 156 of the cage 146, the projection 210 can have a greater depththan the depth of the projection 174.

The cage 146 may be mounted to the card 124 either via a surface-mounttechnology (SMT) operation or via an interference fit using press-fittails as is known in the art. The receptacle connectors 190 electricallyconnects with the card 124 to provide a path for all signal (as shown inFIG. 37) or just the low speed signals and power to pass therethrough(as shown with respect to FIG. 22. Thus the features provided in FIGS.13-25 can also be used with the connector depicted in FIGS. 34-37. Thechannels 176, 212 between the fins 172, 208 of the connector assemblies120 align with the air flow openings 38 such that air flows throughopenings 38 and through the channels 176, 212.

FIGS. 28-33 provide a modified embodiment of a cage 146′ which can bemounted to the card 124 to form the card assembly 120′ (which caninclude contact pads. not shown). As can be appreciated from FIGS.28-33, in one embodiment the connector can be a stacked connector andinclude a top mounted riding heat sink, an internal riding heat sink anda bottom mounted riding heat sink, where the fins of the top and bottommounted riding heat sinks are positioned on opposite sides of thesubstrate. and the bottom riding heat sink extends through the substrateand the cage. The embodiment of FIGS. 28-33 have similarities to theembodiment of FIGS. 27A, 27B and 34-37 and only the differences aredescribed herein. As shown in FIGS. 28-33, the cage 146′ has beenmodified to include an intermediate heat sink assembly housing 230 suchthat an upper port 232 is provided above the intermediate heat sinkassembly housing 230 and a lower port 234 is provided below theintermediate heat sink assembly housing 230. The intermediate heat sinkassembly housing 230 provides a mount for a third heat sink assembly 236within the cage 146′.

The intermediate heat sink assembly housing 230 includes upper and lowerwalls 238, 240 which are spaced apart from each other, but are connectedto each other by a front wall 242 which extends between front ends ofthe upper and lower walls 238, 240, and support walls 244 extendingbetween the upper and lower walls 238, 240 at positions which are spacedfrom the front wall 242. The front wall 242 has a plurality of openings246 therethrough to allow air flow therethrough. The upper and lowerwalls 238, 240 may have a plurality of openings therethrough to allowair flow therethrough. A heat sink hole 248 is provided through thelower wall 240 and is spaced from the front and rear edges thereof.

The heat sink assembly housing 230 is mounted within the cage 146′ suchthat side edges of the upper and lower walls 238, 240 are proximate tothe inner surfaces of the respective side walls 158, 160 of the cage146′. The front wall 242 generally aligns with front edges of the walls154, 156, 158, 160 of the cage 146′. A rear end of heat sink assemblyhousing 230 aligns with, or generally aligns with, a front edge of theopening 194 through the bottom wall 156. The upper and lower walls 238,240 are suitably secured to the side walls 158, 160 of the cage 146′,for example by locking tabs seating with apertures. The heat sinkassembly housing 230 and portions of the side walls 158, 160 of the cage146′ form a heat sink assembly retaining space 250 in which the thirdheat sink assembly 236 is mounted.

The third heat sink assembly 236 is formed from a thermally conductivematerial and includes a heat sink 252 and a clip 254 which attaches theheat sink 252 to the upper wall 238 of the heat sink assembly housing230. As shown, the heat sink 252 includes a base 256 having an uppersurface 256 a and a planar lower surface 256 b which extends from afront end of the base 256 to a rear end of the base 256, a plurality ofconductive fins 258 extending outwardly from the upper surface 256 a,and a projection 260 extending downwardly from the lower surface 256 bof the base 256. The projection 260 has a planar surface 260 a whichspaced from the lower surface 256 b, but is parallel thereto. Thedistance between the surfaces 260 a, 256 b defines a depth of theprojection 260. In an embodiment as shown in the drawings, the fins 258are elongated and extend from the front end of the base 256 to the rearof the base 256, such that elongated channels 262 are formedtherebetween. The lower surface of the base 256 of the heat sink 252seats against the upper surface of the lower wall 240 and the projection260 extends through the heat sink hole 248 such that the projection 260enters into the lower port 234.

The upper port 232 is formed by the top wall 154, an upper portion ofthe side walls 158, 160 above the upper wall 238 of the intermediateheat sink assembly housing 230, and the upper wall 238 of theintermediate heat sink assembly housing 230. The projection 174 of thefirst heat sink assembly 150 extends into the upper port 232. The lowerport 234 is formed by the bottom wall 156, a lower portion of the sidewalls 158, 160 below the lower wall 240 of the intermediate heat sinkassembly housing 230, and the lower wall 240 of the intermediate heatsink assembly housing 230. The projection 210 of the second heat sinkassembly 192 extends into the lower port 234.

When a plug module is inserted into upper port 232 of the cage 146′, theplug module engages with the surfaces 174 a, 201 a of the projections174, 210 and with an upper card slot 264 of the receptacle connector190. To cool the inserted plug module inserted into the upper port 232of the cage 146′, the fins 175 conduct heat away from the plug modulemounted in the upper port 232 of the cage 146′and dissipate heat byconvection. When a plug module is inserted into the lower port 234 ofthe cage 146′, the plug module engages with the projections 210, 260 andwith a lower card slot 266 of the receptacle connector 190. The clips204, 254 may allow the base 206, 256 of the respective heat sink 202,252 to move away from the respective lower walls 156, 240 when the plugmodule is inserted. To cool the inserted plug module inserted into thelower port 234 of the cage 146′, the fins 208, 258 conduct heat awayfrom the plug module mounted in the lower port 234 of the cage 146′anddissipate heat by convection.

The use of heat sinks 252, 202 on opposite sides of the inserted lowerplug module allows for decreased thermal resistance between the lowerplug module and the cooler air, and thus helps improve thermalperformance under load. As can be appreciated, with the depicted designan inserted lower plug module can be cooled from both sides whilekeeping the fins 258, 208 shorter to help reduce the thermal resistancebetween the inserted plug module and the end of the fins 404, 420. Sincethe projection 210 extends through both of the front circuit board 124and the bottom wall 156 of the cage 146′, the projection 210 has agreater depth than the depth of the projection 260. The projections 174,260 may have the same depth.

While the front circuit board 124 is shown positioned below the I/Oconnector assemblies 20 in FIGS. 27A-37, the components can be flippedin the box 22 such that the front circuit board 124 is positioned abovethe I/O connector assemblies 20 in the box 22.

FIGS. 3-25 depict an embodiment of a plurality of card assemblies 357housed in a box 322 which provides enhanced thermal dissipation. Ratherthan mount the two IO connectors in a belly to belly arrangement (whichtypically requires that the plug in the top port has the oppositeorientation of the plug in the bottom port and is shown in FIG. 1), theports are arranged vertically with a top port sharing a side with abottom port by providing a card assembly 357 (FIG. 9) that supports thetwo IO ports, which could be QSFP connectors or any other desirableconnector configuration. The I/O connector assemblies 320 are mounted toand electrically connected to a front circuit board 324 which ishorizontally mounted in the box 322 for transmitting low speed signalsfrom the I/O connector assemblies 320 thereto. The connector assemblies320 are further connected to a rear circuit board 326 in a bypassarrangement for transmitting high speed signals from the I/O connectorassemblies 320 to the rear circuit board 326. Plug modules (not shown)can be inserted in the I/O connector assemblies 320. The plug modulesmay be Quad Small Form Factor (QSFP) transceiver modules or any othersuitable module configuration (such as, without limitation, QSDP-DD,SFP, CXP, OSFP, etc.). High speed signals from the plug modules arerouted via cables from the I/O connector assemblies 320 to the rearcircuit board 326. Low speed signals and power are routed via thecircuit board 324. It should also be noted that in certain embodimentsthe rear circuit board 326 and the circuit board 324 can be the samecircuit board.

The box 322 (not show in its entirety as only the front wall is shown)is typically rectangular in shape (like a typical switch that can bemounted in a rack system) and can have the traditional six sides with afront wall 328 having a front face 328 a that has a plurality of pairsof stacked openings 330 provided therethrough formed in rows and columnsEach opening 330 is provided by an I/O connector assembly and extendsvertically relative to top and bottom edges 328 b, 328 c of the frontwall 328. As such, a top row 332 of spaced apart openings 330 isprovided, and a bottom row 334 of spaced apart openings 330 is provided.Adjacent pairs of openings 330 (one in the top row 332 and one in thebottom row 334) are spaced apart from each other by a section 336 of thefront wall 328. As shown, the openings 330 form sets two openings 330between sections 336, however in other embodiments the numbers ofopenings 330 may vary. Each section 336 of the front wall 328 has aplurality of air flow openings 338 provided therethrough which allow airto flow through the front wall 328 to cool the I/O connector assemblies320 mounted therein. Thus, the front wall 328 can be configured todecrease air resistance so as to allow for more air to flow through thebox 322 for a given air pressure gradient.

A frame-like structure can be provided in the box and can include sidewalls 342, 344 that extend rearwardly from the front wall 328 along witha top brace 340. The front circuit board 324 is mounted in a horizontalorientation and can be positioned below the bottom row 334 of openings330.

Examples of card assemblies are shown in FIGS. 7, 16 and 19. Notably,the embodiment in FIG. 7 only includes a first heat sink on one side ofa card and omitting a second heat sink on a second side of the card). Ascan be appreciated, for additional cooling, the card can have anaperture in the middle and a second heat sink assembly can be mountedthereon so that the second heat sink assembly has projections thatextend into the cage. As with the first heat sink assembly, the heatsink can be a single unit or multiple units. For example, in anembodiment the heat sink can be a riding heat sink such as is known.Naturally the use of two riding heat sinks on opposite sides of themodule allows for decreased thermal resistance between the module andthe cooler air and thus helps improve thermal performance under load.The ability to have both heat sinks flex potentially allows for stifferretaining clips on both sides that collectively equal the stiffness ofwhat would normally be a single retaining clip. The expectation is thatsuch an increase in stiffness may provide an improved thermal interfaceon both sides of the inserted module while providing a consistent levelof insertion force. As can be appreciated, therefore, in certainembodiments an inserted module can be cooled from both sides whilekeeping the fins shorter to help reduce the thermal resistance betweenthe inserted module and the end of the fins.

As can be appreciated, the card may have two apertures, one aligned witheach port. Such a configuration allows for a center portion of the cardto accept mounting tails from the cage and thus potentially provides amore secure/robust structure. Such a construction is not required,however and a single aperture that is aligned with both ports is alsosuitable for certain applications. In an embodiment the apertures aresized so that the connector extends over the aperture. In such anembodiment, as can be appreciated, the increased size of the apertureallows for greater surface area for the mating heat sink to engage aninserted module. Naturally, the size of the aperture (and thecorresponding size of the projection on the heat sink) can be adjustedto account for thermal performance requirements.

As depicted, the contact pads on the card are positioned between a topand bottom edge of the card. Conventional cards have contact pads on thebottom for stability purposes and the depicted embodiment would be lessdesirable from a stability standpoint. Having the contact pads offsetfrom the top or bottom, however, allows for improvements in packagingthat has been determined in certain cases to be more valuable than thestability provided by a conventional design. Additional stability, ifdesired, can be provided by ensuring the cage securely engages a frontpanel.

As depicted, the card assembly 357 has the I/O connector assemblies 320mounted on a card 358 and each I/O connector assembly 320 includes aconductive cage 346 having a front end 346 a and a rear end 346 b andthe respective conductive cage 346 defines the opening 330 and furtherdefines an upper port 348 extending from the front end 346 a toward therear end 346 b thereof and a lower port 350 extending from the opening330 in front end 346 a toward the rear end 346 b thereof. The cardassembly 357 further includes an upper receptacle connector 352 mountedin the upper port 348 of the cage 346, and a lower receptacle connector354 mounted in the lower port 350 of the cage 346. Both of thereceptacle connectors 352, 354 have a front edge 391. The card assembly357 further includes a first heat sink assembly 356 mounted to the cage346, the card 358, which can be a conventional circuit board or someother substrate with a desired configuration, to which the cage 346 andthe receptacle connectors 352, 354 are mounted to one side thereof, anda second heat sink assembly 360 mounted to the cage 346 and to the card358. The card assembly 357 further includes a cable assembly 362connected to the receptacle connectors 352, 354. As can be appreciated,the card 358 can be positioned vertically within the box 322 and thus beperpendicular to the front circuit board 324. It should be noted thatthe card assembly 357 can be mounted with the contact pads 432 facingupward or downward. As a result, the use of upper and lower ports is forease of discussion as the orientation can be reversed depending on howthe card assembly 357 is mounted in the box.

The cage 346 includes an upper wall 364, parallel side walls 366, 368extending downwardly therefrom at opposite side edges thereof to a lowerwall 370 which is parallel to the upper wall 364. An intermediate wall372 extends between the side walls 366, 368 and is parallel to the upperand lower walls 364, 366. The upper port 348 is formed by the upper wall364, an upper portion of the side walls 366, 368 and the intermediatewall 372. The lower port 350 is formed by the lower wall 370, a lowerportion of the side walls 366, 368 and the intermediate wall 372.

The side wall 366 has an upper opening 374 proximate to the front end346 a of the cage 346 above the intermediate wall 372 and which is incommunication with the upper port 348. The upper opening 374 has a frontedge 374 a, an opposite rear edge 374 b and top and bottom edges 374 c,374 d extending between the front and rear edges 374 a, 374 b. In anembodiment, the upper opening 374 is rectangular. The side wall 368further has a lower opening 376 proximate to the front end 346 a of thecage 346 below the intermediate wall 372 and which is in communicationwith the lower port 350. The lower opening 376 has a front edge 376 a,an opposite rear edge 376 b and top and bottom edges 376 c, 376 dextending between the front and rear edges 376 a, 376 b. In anembodiment, the lower opening 376 is rectangular. The openings 374, 376are aligned with each other.

The side wall 368 has an upper opening 378 proximate to the front end346 a of the cage 346 above the intermediate wall 372 and which is incommunication with the upper port 348. The upper opening 378 has a frontedge 378 a, an opposite rear edge 378 b and top and bottom edges 378 c,378 d extending between the front and rear edges 378 a, 378 b. In anembodiment, the upper opening 378 is rectangular. The side wall 368further has a lower opening 380 proximate to the front end 346 a of thecage 346 below the intermediate wall 372 and which is in communicationwith the lower port 350. The lower opening 380 has a front edge 380 a,an opposite rear edge 380 b and top and bottom edges 380 c, 380 dextending between the front and rear edges 380 a, 380 b. In anembodiment, the lower opening 380 is rectangular. The openings 378, 380are aligned with each other.

The side wall 368 has an upper opening 382 at the rear end 346 b of thecage 346 above the intermediate wall 372 and which is in communicationwith the upper port 348. The upper receptacle connector 352 is mountedthrough the upper opening 382 and into the upper port 348. The side wall368 further has a lower opening 384 at the rear end 346 b of the cage346 below the intermediate wall 372 and which is in communication withthe lower port 350. The lower receptacle connector 354 is mountedthrough the lower opening 384 and into the lower port 350. The openings382, 384 are aligned with each other such that the receptacle connector354 is above the receptacle connector 352.

Spring fingers 386 may be provided on the walls 364, 366, 368, 370 toassist in connecting the cage 346 to the front wall 328 of the box 322.The cage 346 may be formed by stamping and forming. The cage 346 isthermally conductive and forms a shield assembly for the componentsmounted therein. When the cages 346 are connected to the front wall 328of the box 322, the front ends 346 a of the cages 346 form ports throughthe front wall 328.

The receptacle connectors 352, 354 are shown in FIGS. 19-21. Eachreceptacle connector 352, 354 includes a housing 388 have a card slot390 open to a front end thereof, and into which a paddle card (notshown) of the plug module is received. A plurality of terminals withinthe card slot 390 connect with the paddle card. As depicted, eachreceptacle connector 352, 354 further has a plurality of laterallyspaced wafers 392 which connect with the cable assembly 362. It shouldbe noted that other configurations are contemplated such as having thehigh-speed signals configured in vertical wafers (relative to thehorizontal card slot) while low speed signal are connected to the card358 in a group similar to conventional SMT style terminals. High speedsignals are transmitted from the plug module, through the terminals inthe card slot 390 and then to the cable assembly 362. Low speed signalsand power are routed via the paddle card, terminals 394 in thereceptacle connector which extend through the side wall 368 and whichare connected to the card 358. In an embodiment, the front ends of thereceptacle connectors 352, 354 are rearward of the rear edges 378 b, 380b of the openings 378, 380. In an alternate embodiment, the front endsof the receptacle connectors 352, 354 overlap the rear edges 378 b, 380b of the openings 378, 380.

The first heat sink assembly 356 is formed from a thermally conductivematerial and includes an upper heat sink 396, a lower heat sink 398, anda clip 400 which attaches the heat sinks 396, 398 to the side wall 366of the cage 346. As shown, each heat sink 396, 398 includes a base 402having a first side surface 402 a and a planar second side surface 402 bwhich extends from a front end 402 c of the base 402 to a rear end 402 dof the base 402, a plurality of conductive fins 404 extending outwardlyfrom the first side surface 402 a, and a projection 406 extendingoutwardly from the second side surface 402 b. Each projection 406 has aplanar surface 406 a which spaced from the second side surface 402 b butis parallel thereto. The distance between the surfaces 406 a, 402 bdefines a depth of each projection 406. In an embodiment as shown in thedrawings, the fins 404 are elongated and extend from the front end 402 cto the rear 402 d, such that elongated channels 408 are formedtherebetween. As shown, multiple sets of fins 404 may be provided, withthe sets of fins 404 being separated by sections 410 of the first sidesurface 402 a of the base 402. In an alternative embodiment (not shown),the fins 404 are formed in an array of pillars.

The second side surface 402 b of the base 402 of the upper heat sink 396seats against an outer surface of the side wall 366. The projection 406of the upper heat sink 396 extends through the upper opening 374 in theside wall 366 of the cage 346 and into the upper port 348 thereof. Thesecond side surface 402 b of the base 402 of the lower heat sink 398seats against an outer surface of the side wall 366. The projection 406of the lower heat sink 398 extends through the lower opening 376 in theside wall 366 of the cage 346 and into the lower port 350 thereof. Theclip 400 attaches to the top and bottom walls 154, 156 to attach theheat sinks 396, 398 to the side wall 366 of the cage 146, and in anembodiment, the clip 400 is seated in the sections 410.

The second heat sink assembly 360 is formed from a thermally conductivematerial and includes an upper heat sink 412, a lower heat sink 414, anda clip 416 which attaches the heat sinks 412, 414 to the side wall 366of the cage 346. As shown, each heat sink 412, 414 includes a base 418having a first side surface 418 a and a planar second side surface 418 bwhich extends from a front end 418 c of the base 418 to a rear end 418 dof the base 418, a plurality of conductive fins 420 extending outwardlyfrom the first side surface 418 a, and a projection 422 extendingoutwardly from the second side surface 418 b. Each projection 422 has aplanar surface 422 a which spaced from the second side surface 418 b butis parallel thereto. The distance between the surfaces 422 a, 418 bdefines a depth of each projection 422. In an embodiment as shown in thedrawings, the fins 420 are elongated and extend from the front end 418 cto the rear 418 d, such that elongated channels 424 are formedtherebetween. As shown, multiple sets of fins 420 may be provided, withthe sets of fins 420 being separated by sections 426 of the first sidesurface 418 a of the base 418. In an alternative embodiment (not shown),the fins 420 are formed in an array of pillars.

The card 358 has a front portion 428 which overlays and is connected tothe side wall 368 of the cage 346, and a rear portion 430 which extendsoutwardly from the rear end of the front portion 428 and the rear end326 b of the cage 346. The rear portion 430 has a plurality of contactpads 432, which are arranged in a row, provided on an edge thereof andwhich connect to the front circuit board 324 by connectors 434. The rearportion 430 thus provides a mounting flange for attachment of the card358 to the front circuit board 324. In an embodiment, the contact pads432 are provided on a lower edge 430 a of the rear portion 430 and thefront circuit board 324 lays below the rear portions 430; the connector434 is used to electrically connect the contact pads 432 to the frontcircuit board 324 such that the front circuit board 324 is supported bythe card 358. In an embodiment as shown in FIGS. 6-11, the contact pads432 are provided on an upper edge 430 b of the rear portion 430 (itbeing understood that rotating the card 180 degrees would cause theupper edge to be a lower edge) and the front circuit board 324 lays ontop of the rear portions 430 430; a connector is used to electricallyconnect the contact pads 432 on each rear portion 430 to the frontcircuit board 324 such that the front circuit board 324 is supported bythe card 358 (or in alternative embodiments, the circuit board 324 helpssupport the card 358). It should be noted that the connector 434 isshown as a vertical style board connector (in that the mating contactpads are inserted into the connector 434 in a vertical direction). In anembodiment, the contact pads 432 are provided on a rear edge 430 c ofthe rear portion 430 and the front circuit board 324 lays on top of therear portions 430 or below the rear portions 430; a right-angleconnector is used to electrically connect the contact pads 432 to thefront circuit board 324 such that the front circuit board 324 issupported by the card 358. In an embodiment, the contact pads 432 areprovided on the upper edge 430 b of the rear portion 430 and on the rearedge of the rear portion 430; the front circuit board 324 lays on top ofthe rear portions 430 and are connected to the contact pads 432 byconnectors such that the front circuit board 324 is supported by thecard 358. In an embodiment, the contact pads 432 are provided on thelower edge 430 a of the rear portion 430 and on the rear edge 430 c ofthe rear portion 430; the front circuit board 324 lays below the rearportions 430 and are connected to the contact pads 432 by connectorssuch that the front circuit board 324 is supported by the card 358. Inan embodiment, the contact pads 432 are provided on the lower and upperedges 430 a, 430 b of the rear portion 430; a first front circuit board324 lays above the rear portions 430 and are connected to the contactpads 432 on the upper edge by connectors such that the first frontcircuit board 324 is supported by the card 358; and a second frontcircuit board 324 lays below the rear portions 430 and are connected tothe contact pads 432 on the lower edge by connectors such that thesecond front circuit board 324 is supported by the card 358.

When the front circuit board 324 is connected to the lower edges 430 aof the rear portions 430, the lower edge 430 a of each rear portion 430is vertically spaced above the lower wall 370 of the respective cage346. When the front circuit board 324 is connected to the upper edges430 b of the rear portions 430, the upper edge 430 b of each rearportion 430 is vertically spaced below the upper wall 364 of therespective cage 346. This provides a space for the front circuit board324 to be positioned directly behind the cage 346 and not use additionalvertical space in the box 322.

The side wall 368 of the cage 346 is attached to the front portion 428,such that the rear portion 430 is cantilevered outwardly from the cage346. The side wall 368 of the cage 346 is connected to the card 358either via a surface-mount technology (SMT) operation or via aninterference fit using press-fit tails as is known in the art. If thecages 346 are pressed on the card 358 with the use of press-fit tailsthen a solder operation is not needed and additional choices in thetypes of materials that will work are possible. The receptacleconnectors 352, 354 are electrically connected to the card 358 and maybe surface-mounted to the card 358, or may have press-fit tails whichextend into conductive vias in the card 358 as is known in the art.

The front portion 428 of the card 358 has an upper opening or port 436proximate to the front end 346 a of the cage 346 above the intermediatewall 372 and which is in communication with the upper port 348. Theupper port 436 has a front edge 436 a, an opposite rear edge 436 b andtop and bottom edges 436 c, 436 d extending between the front and rearedges 436 a, 436 b. In an embodiment, the upper port 436 is rectangular.The card 358 further has a lower aperture 438 proximate to the front end346 a of the cage 346 below the intermediate wall 372 and which is incommunication with the lower port 350. The lower aperture 438 has afront edge 438 a, an opposite rear edge 438 b and top and bottom edges438 c, 438 d extending between the front and rear edges 438 a, 438 b. Inan embodiment the front edge 391 of the receptacle connectors extendspast the rear edge 43 8 b and thus the receptacle connector can overlapthe aperture 438 (and similarly the aperture 436). In an embodiment, thelower aperture 438 is rectangular. The apertures 436, 438 are alignedwith each other. In an embodiment, a front edge 428 a of the frontportion 428 aligns with the front end 346 a of the cage 346, a rear edge428 b of the front portion 428 is rearward of the rear end 346 b of thecage 346, a top edge 428 c of the front portion 428 aligns with theupper wall 364 of the cage 346, and a bottom edge 428 d of the frontportion 428 aligns with the lower wall 370 of the cage 346. A firstplanar side surface 428 e extends between the edges 428 a-428 d abutsagainst the side wall 368, and a second planar side surface 428 fextends between the edges 428 a-428 d on the opposite side of the frontportion 428.

The rear portion 430 of the card 358 has a first planar side surface 430d that extends between the edges 430 a-430 c and is coplanar with thefirst planar side surface 428 e of the front portion 428, and a secondside surface 430 e that extends between the edges 430 a-430 c on theopposite side of the rear portion 430 and is coplanar with the secondside surface 428 f.

The second heat sink assembly 360 is assembled to the card 358 and tothe cage 346 by the clip 416. The second side surface 418 b of the base418 of the upper heat sink 412 seats against the second side surface 428f of the card 358. The projection 422 of the upper heat sink 412 extendsthrough the upper aperture 436 in the card 358, through the upperopening 378 in the side wall 368 of the cage 346 and into the upper port348 thereof. The second side surface 418 b of the base 418 of the lowerheat sink 414 seats against the second side surface 428 f of the card358. The projection 422 of the lower heat sink 414 extends through thelower aperture 438 in the card 358, through the lower opening 380 in theside wall 368 of the cage 346 and into the lower port 350 thereof. Theclip 416 extends through openings 216 in card 358 and engage with theupper and lower walls 364, 370 of the cage 346. In an embodiment, theclip 400 is seated in the sections 410.

A plug module (not shown) is inserted through the front end 346 a of thecage 346, into the upper port 348 and engages with the upper receptacleconnector 352 in a known manner. The plug module forms a primaryelectromagnetic containment and the cage 346 forms a conductive sleevearound the plug module. When the plug module is inserted into the upperport 348 of the cage 346, the plug module engages with the surfaces 406a, 422 a projections 406, 422 of the upper heat sinks 396, 412 and withthe card slot 390 of the upper receptacle connector 352. The clips 400,416 may allow the base 402, 418 of the respective upper heat sink 396,412 to move away from the respective side walls 366, 368 when the plugmodule is inserted into the upper port 348. To cool the plug moduleinserted into the upper port 348, the fins 404, 420 conduct heat awayfrom the plug module inserted into the upper port 348 and can dissipateheat by convection.

Likewise, a plug module (not shown) is inserted through the front end346 a of the cage 346, into the lower port 350 and engages with thelower receptacle connector 354 in a known manner. The plug module formsa primary electromagnetic containment and the cage 346 forms aconductive sleeve around the plug module. When the plug module isinserted into the lower port 350 of the cage 346, the plug moduleengages with the surfaces 406 a, 422 a on the projections 406, 422 ofthe lower heat sinks 398, 414 and with the card slot 390 of the lowerreceptacle connector 354. The clips 400, 416 may allow the base 402, 418of the respective lower heat sink 398, 414 to move away from therespective side walls 366, 368 when the plug module is inserted into thelower port 350. To cool the plug module inserted into the lower port350, the fins 404, 420 conduct heat away from the plug module insertedinto the lower port 350 and dissipate heat by convection. As a result,this embodiment allows each plug module to be inserted into the ports348, 350 in the same direction.

As depicted, since the projections 422 extends through both of the card358 and the side wall 368 of the cage 146′, the projection 422 has agreater depth than the depth of the projections 406. As can beappreciated, while the base 402 of the upper heat sink 396 is shownseparated from the base 402 of the lower heat sink 398, a singlecontinuous base can be provided.

While the base 418 of the upper heat sink 412 is shown separated fromthe base 418 of the lower heat sink 414, a single continuous base can beprovided as shown in FIG. 18. While two separate apertures 436, 438 areshown in the drawings through the card 358, a single opening can beprovided therethrough which will accommodate both projections 422 on theupper and lower heat sinks 412, 414.

The use of heat sinks 396, 398, 414, 416 on opposite sides of each plugmodule allows for decreased thermal resistance between the plug moduleand the cooler air, and thus helps improve thermal performance underload. As can be appreciated, with the depicted design an inserted plugmodule can be cooled from both sides while keeping the fins 404, 420shorter to help reduce the thermal resistance between the inserted plugmodule and the end of the fins 404, 420.

As shown in FIG. 20, the front end of the receptacle connector 352, 354can overlap the rear end 436 b, 438 b of the respective apertures 436,438. The projections 422 on the upper and lower heat sinks 412, 414 maybe contact with the front ends of the receptacle connectors 352, 354that overlap the rear end 436 b, 438 b of the respective apertures 436,438. This assists in dissipating heat from the receptacle connectors352, 354.

The cable assembly 362 includes a plurality of cables 440 connected tothe upper receptacle connector 352 for transmitting high speed signalsfrom the plug module to the rear circuit board 326, and plurality ofcables 442 connected to the lower receptacle connector 354 fortransmitting high speed signals from the plug module to the rear circuitboard 326. The cables 440 are terminated with connectors 446 and thecables 442 are terminated with a connector 448. As shown in FIG. 11, thefront circuit board 324 can be formed of rigid sections 450 attached tothe cards 358 on which the connectors 434 are mounted and a flex circuit452 connecting the rigid sections 450 together. As can be appreciated,when adjacent card assemblies 357 are mounted on the front circuit board324, the fins 404 on the heat sink assembly 356 faces the fins 420 onthe heat sink assembly 360 on adjacent card assemblies as shown in FIG.13.

In an embodiment as shown in FIGS. 26A and 26F, the rear portion 430 ofthe card 358 has a block 454 formed of an insulative material whichextends outwardly from each of the side surfaces 430 d, 430 e. Eachblock 454 extends from the edge on which the contact pads 432 areprovided and extends from the rear edge 430 c of the rear portion 430.The connectors 434 on the front circuit board 324 have an opening 456into which the blocks 454 are accepted. The blocks 454 assist inproperly orienting the card 358 and the connector 434.

To further support adjacent card assemblies mounted on the front circuitboard 324, a support member 460 as shown in FIGS. 26A-26H can beprovided between the adjacent card assemblies 357 to provide furtherrigidity to the assembly. The support member 460 is suitably secured inthe box 322. The support member 460 is preferably made of a conductivematerial but can be made of insulative materials for easier forming andlower cost (but also with lower thermal performance). The support member460 is described in the orientation shown in FIGS. 26A-26H for ease indescription, however, when the I/O connector assemblies 320 are providedsuch that the contact pads 432 are on the upper edge 430 b of the rearportion 430, the support member 460 would be rotated 180 degrees in usefrom the orientation shown in FIGS. 26A-26H.

In an embodiment, the support member 460 may generally be formed as anI-beam and has a top horizontally extending wall 462 having a front end462 a and a rear end 462 b, a bottom horizontally extending wall 464having a front end 464 a and a rear end 464 b, and a vertical connectingwall 466 connecting the top and bottom walls 462, 464 together.

The top wall 462 has a top surface 462 c, a bottom surface 462 d, afirst side edge 462 e extending from the front end 462 a to the rear end462 b and between the top and bottom surfaces 426 c, 426 d, and anopposite second side edge 462 f extending from the front end 462 a tothe rear end 462 b and between the top and bottom surfaces 426 c, 426 d.The bottom surface 462 d is planar. A plurality of notches 468 areprovided in the top wall 462 and extend from the first side edge 462 e.A plurality of notches 470 are provided in the top wall 462 and extendfrom the second side edge 462 f.

The bottom wall 464 has a top surface 464 c, a bottom surface 464 d, afirst side edge 464 e extending from the front end 464 a to the rear end464 b and between the top and bottom surfaces 426 c, 426 d, and anopposite second side edge 464 f extending from the front end 464 a tothe rear end 464 b and between the top and bottom surfaces 426 c, 426 d.The bottom surface 464 d is planar. A plurality of notches 472 areprovided in the bottom wall 464 and extend from the first side edge 464e. A plurality of notches 474 are provided in the bottom wall 464 andextend from the second side edge 464 f. The top surface 464 c of thebottom wall 464 faces the bottom surface 462 d of the top wall 462. Thebottom wall 464 is shorter in length than the top wall 462.

The vertical connecting wall 466 has a front section 476 which extendsfrom the front ends 462 a, 464 a of the top and bottom walls 462, 464 toa rear section 478 which extends from the front section 476 to the rearend 462 b of the top wall 462. The front section 476 extends to the rearend 464 b of the bottom wall 464. The front section 476 has a frontsurface 476 a, a rear surface 476 b, a first side surface 476 cextending between the front and rear surfaces 476 a, 476 b, and a secondside surface 476 d extending between the front and rear surfaces 476 a,476 b. A width of the front section 476 is defined between the sidesurfaces 476 c, 476 d.

The rear section 478 has a front end 478 a, a rear surface 478 b, afirst side surface 478 c extending between the front end 478 a and therear surface 478 b, a second side surface 478 d extending between thefront end 478 a and the rear surface 478 b, and a lower end surface 478e extending between the front end 478 a and the rear surface 478 b. Awidth of the rear section 478 is defined between the side surfaces 478c, 478 d. A notch 480 is defined by the rear surface 476 b of the frontsection 476 and the lower end surface 478 e of the rear section 478.

A first pair of vertically spaced apart openings 482, 484 are providedthrough the front section 476 rearward of a front surface 476 a thereofsuch that a first upper opening 482 is provided and a first loweropening 484 is provided which are separated by a first horizontalportion 486 of the front section 476. A second pair of vertically spacedapart openings 488, 490 are provided through the front section 476rearward of the first pair of openings 482, 484 such that a second upperopening 488 is provided and a second lower opening 490 is provided whichare separated by a second horizontal portion 492 of the front section476. The first pair of openings are 482, 484 separated from the secondpair of openings 488, 490 by a vertical portion 494 of the front section476. A front vertical portion 496 of the front section 476 is definedforward of the openings 482, 484, and a rear vertical portion 498 of thefront section 476 is defined rearward of the openings 488, 490.

The front vertical portion 496 has a width which is the same as thewidth of the horizontal portions 486, 492. The front vertical portion496 has a plurality of openings 500 which extend from the front surface476 a to the openings 482, 484. The vertical portion 494 has a widthwhich is less than front vertical portion 496 and the horizontalportions 486, 492 and is provided in the middle of the horizontalportions 486, 492. The rear vertical portion 496 has a width which isless than front vertical portion 496 and the horizontal portions 486,492 and is offset to the second side surface 476 d.

The rear section 478 has a front portion 504 which has a width which isequal to the rear vertical portion 498 and aligns with the rear verticalportion 498, and a rear portion 506 which extends from the front portion504 and has a width which is equal to the front vertical portion 496.Openings 508 extend through the rear portion 506 from the front endthereof which is proximate to the front portion 504 to the rear surface478 b of the vertical connecting wall 466.

Horizontally extending spaced apart ribs 510 extend outwardly from thefirst side surfaces 476 c, 478 c of the rear vertical portion 496 of thefront section 476 and the front portion 504 of the rear section 478.Horizontally extending spaced apart ribs 512 extend outwardly from thesecond side surfaces 476 d, 478 d of the rear vertical portion 496 ofthe front section 476 and the front portion 504 of the rear section 478.As such, a first pocket 514 is formed by on one side of the verticalconnecting wall 466, and a second pocket 516 is formed by on the otherside of the vertical connecting wall 466.

When the card assemblies 357 are attached to the support member 460, thecard 358 of each card assembly 357 seats within the respective pocket514, 516 and feet on the card 358 of each card assembly 357 seats withinthe notches 468, 470, 472, 474 and may engaged by a friction fit orpermanently secured thereto. The card 358 seated within pocket 514engages against the front vertical portion 496, the horizontal portions486, 492, and the ribs 510. The card 358 seated within pocket 516engages against the front vertical portion 496, the horizontal portions486, 492, and the ribs 512. The card 358 of each card assembly 357 isspaced from the vertical portion 494. As a result, air can flow from thefront of the support member 460 to the rear of the support member 460between the cards 358 and the support member 460. The fins 420 seatwithin the pockets 514, 516 on each side of the support member 460.

As shown in FIGS. 26C and 26F, in an embodiment, a cover 518 is attachedto the free end of the fins 420. The cover 518 is preferably a thermallyconductive material. The cover 518 may be attached to the fins 420 byconductive adhesive. In addition, light pipes may be provided in the I/Oconnector assemblies 320.

The disclosure provided herein describes features in terms of preferredand exemplary embodiments thereof. Numerous other embodiments,modifications and variations within the scope and spirit of the appendedclaims will occur to persons of ordinary skill in the art from a reviewof this disclosure.

We claim:
 1. A card assembly, comprising: a card with a front portionand a rear portion and a first side and a second side and an apertureextending between the first and second sides and contact pads positionedin the rear portion; an I/O cage assembly mounted on the first side ofthe card, the I/O cage assembly having a cage that defines a port with afront opening and having a receptacle connector positioned in the portand configured to engage a plug module inserted into the port, the cageincluding a first opening and a second opening, the first and secondopenings being positioned on opposite sides of the cage, the secondopening being aligned with the aperture; a first heat sink assemblypositioned on the cage and having a first projection that extends intothe first opening so as to extend into the port; and a second heat sinkassembly positioned on the second side of the card, the second heat sinkhaving a second projection that extends through the aperture and thesecond opening so as to extend into the port.
 2. The card assembly ofclaim 1, wherein the I/O cage assembly is a first I/O cage assembly andthe aperture being a first aperture, the card having a second apertureand supporting a second I/O cage assembly aligned with the secondaperture, wherein the port is a first port and the second I/O cageassembly defining a second port.
 3. The card assembly of claim 2,wherein the card is configured to be aligned vertically.
 4. The cardassembly of claim 1, wherein the first heat sink assembly is a ridingheat sink configured to engage a plug module respectively inserted intothe first and second ports.
 5. The card assembly of claim 1, furthercomprising a cable assembly extending from the I/O cage assembly, thecable assembly configured to pass high speed signal from the connectorto a connector system adjacent a chip package.
 6. The card assembly ofclaim 1, wherein the first heat sink assembly is a riding heat sink
 7. Acomputing box, comprising: a box with a front face; a circuit boardarranged in a horizontal manner in the box, the circuit board spacedapart from the front face, the circuit board having a board connectormounted thereon; and a card assembly mounting to the circuit board, thecard assembly comprising: a card with a front portion and a rear portionand a first side and a second side and an aperture extending between thefirst and second sides and contact pads positioned in the rear portion,the contact pads engaging the board connector; an I/O cage assemblymounted on the first side of the card, the I/O cage assembly including acage that defines a port with a front edge and a receptacle connectorpositioned in the port and configured to engage a plug module insertedinto the port, the front edge of cage being aligned with the front faceof the box, the cage including a first opening and a second opening, thefirst and second openings being positioned on opposite sides of thecage, the second opening being aligned with the aperture; a first heatsink assembly positioned on the cage and having a first projection thatextends into the first opening so as to extend into the port; and asecond heat sink assembly positioned on the second side of the card, thesecond heat sink having a second projection that extends through theaperture and the second opening so as to extend into the port.
 8. Thebox assembly of claim 7, wherein the board connector is configured toreceive the contact pads in a vertical direction.
 9. The box assembly ofclaim 7, wherein the connector is connector to a cable assembly, thecable assembly configured to distribute high speed signal therealong.10. The box assembly of claim 9, wherein the cable assembly is connectedto a connector assembly positioned adjacent a chip package.
 11. The boxassembly of claim 7, wherein the box supports a plurality of cardassemblies positioned adjacent to each other, each of the cardassemblies being arranged in a vertical configuration.
 12. The boxassembly of claim 11, wherein the front face includes a plurality of airflow openings positioned between each the openings provided by theadjacent card assemblies.